Pesticide Tolerances for Emergency Exemptions: Nicosulfuron

Federal Register: February 24, 2010 (Volume 75, Number 36)

Rules and Regulations

Page 8256-8261

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

DOCID:fr24fe10-9

ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 180

EPA-HQ-OPP-2009-0569; FRL-8812-5

Nicosulfuron; Pesticide Tolerances for Emergency Exemptions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

SUMMARY: This regulation establishes time-limited tolerances for residues of nicosulfuron, [3-pyridinecarboxamide, 2-((((4,6- dimethoxypyrimidin-2-yl) aminocarbonyl) aminosulfonyl))-N,N-dimethyl]; in or on Bermudagrass, forage and Bermudagrass, hay. This action is in response to EPA granting crisis exemptions to the Texas Department of

Agriculture and the Oklahoma Department of Agriculture under section 18 of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) authorizing use of the pesticide on Bermudagrass, forage and

Bermudagrass, hay. This regulation establishes maximum permissible levels for residues of nicosulfuron in Bermudagrass and hay. The time- limited tolerances expire and are revoked on December 31, 2011.

DATES: This regulation is effective February 24, 2010. Objections and

Page 8257

requests for hearings must be received on or before April 26, 2010, and must be filed in accordance with the instructions provided in 40 CFR part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).

ADDRESSES: EPA has established a docket for this action under docket identification (ID) number EPA-HQ-OPP-2009-0569. All documents in the docket are listed in the docket index available in http:// www.regulations.gov. Although listed in the index, some information is not publicly available, e.g., Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the

Internet and will be publicly available only in hard copy form.

Publicly available docket materials are available in the electronic docket at http://www.regulations.gov, or, if only available in hard copy, at the OPP Regulatory Public Docket in Rm. S-4400, One Potomac

Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA. The Docket

Facility is open from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The Docket Facility telephone number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Stacey Groce, Registration Division

(7505P), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone number: (703) 305-2505; e-mail address: groce.stacey@epa.gov.

SUPPLEMENTARY INFORMATION:

1. General Information

   1. Does this Action Apply to Me?

      You may be potentially affected by this action if you are an agricultural producer, food manufacturer, or pesticide manufacturer.

      Potentially affected entities may include, but are not limited to:

      Crop production (NAICS code 111).

      Animal production (NAICS code 112).

      Food manufacturing (NAICS code 311).

      Pesticide manufacturing (NAICS code 32532).

      This listing is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be affected by this action. Other types of entities not listed in this unit could also be affected. The North American Industrial Classification System (NAICS) codes have been provided to assist you and others in determining whether this action might apply to certain entities. If you have any questions regarding the applicability of this action to a particular entity, consult the person listed under FOR FURTHER INFORMATION

      CONTACT.

   2. How Can I Get Electronic Access to Other Related Information?

      You may access a frequently updated electronic version of 40 CFR part 180 through the Government Printing Office's e-CFR cite at http:// www.gpoaccess.gov/ecfr.

   3. Can I File an Objection or Hearing Request?

      Under section 408(g) of the Federal Food, Drug, and Cosmetic Act

      (FFDCA), 21 U.S.C. 346a, any person may file an objection to any aspect of this regulation and may also request a hearing on those objections.

      The EPA procedural regulations which govern the submission of objections and requests for hearings appear in 40 CFR part 178. You must file your objection or request a hearing on this regulation in accordance with the instructions provided in 40 CFR part 178. To ensure proper receipt by EPA, you must identify docket ID number EPA-HQ-OPP- 2009-0569 in the subject line on the first page of your submission. All requests must be in writing, and must be mailed or delivered to the

      Hearing Clerk on or before April 26, 2010.

      In addition to filing an objection or hearing request with the

      Hearing Clerk as described in 40 CFR part 178, please submit a copy of the filing that does not contain any CBI for inclusion in the public docket that is described in ADDRESSES. Information not marked confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA without prior notice. Submit your copies, identified by docket ID number EPA-HQ-OPP-2009-0569, by one of the following methods:

      Federal eRulemaking Portal: http://www.regulations.gov.

      Follow the on-line instructions for submitting comments.

      Mail: Office of Pesticide Programs (OPP) Regulatory Public

      Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania

      Ave., NW., Washington, DC 20460-0001.

      Delivery: OPP Regulatory Public Docket (7502P),

      Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South

      Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only accepted during the Docket Facility's normal hours of operation (8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays).

      Special arrangements should be made for deliveries of boxed information. The Docket Facility telephone number is (703) 305-5805.

2. Background and Statutory Findings

   EPA, on its own initiative, in accordance with sections 408(e) and 408(l)(6) of FFDCA, 21 U.S.C. 346a(e) and 346a(1)(6), is establishing time-limited tolerances for residues of the herbicide nicosulfuron, in or on Bermudagrass, forage and Bermudagrass, hay at 10 parts per million (ppm) and 25 (ppm) respectively. These time-limited tolerances expire and are revoked on December 31, 2011. EPA will publish a document in the Federal Register to remove the revoked tolerances from the Code of Federal Regulations (CFR).

   Section 408(l)(6) of FFDCA requires EPA to establish a time-limited tolerance or exemption from the requirement for a tolerance for pesticide chemical residues in food that will result from the use of a pesticide under an emergency exemption granted by EPA under section 18 of FIFRA. Such tolerances can be established without providing notice or period for public comment. EPA does not intend for its actions on

   FIFRA section 18 related time-limited tolerances to set binding precedents for the application of section 408 of FFDCA to other tolerances and exemptions. Section 408(e) of FFDCA allows EPA to establish a tolerance or an exemption from the requirement of a tolerance on its own initiative, i.e., without having received any petition from an outside party.

   Section 18 of FIFRA authorizes EPA to exempt any Federal or State agency from any provision of FIFRA, if EPA determines that ``emergency conditions exist which require such exemption.'' EPA has established regulations governing such emergency exemptions in 40 CFR part 166.

3. Emergency Exemption for Nicosulfuron on Bermudagrass Forage and

   Hay and FFDCA Tolerances

   The Texas and Oklahoma Departments of Agriculture requested emergency exemptions for use of nicosulfuron on Bermudagrass and hay to control field sandbur species, and issued crisis exemptions for this use pursuant to 40 CFR part 166, subpart C of FIFRA. The states provided information indicating that sandbur species is a serious pest that commonly infests Bermudagrass and hay.

   As part of its evaluation of the emergency exemption applications,

   EPA assessed the potential risks presented by residues of nicosulfuron in or on Bermudagrass, forage and Bermudagrass, hay. In doing so, EPA

   Page 8258

   considered the safety standard in section 408(b)(2) of FFDCA, and EPA decided that the necessary tolerances under section 408(l)(6) of FFDCA would be consistent with the safety standard and with FIFRA section 18.

   Consistent with the need to move quickly on the emergency exemptions in order to address urgent non-routine situations and to ensure that the resulting food is safe and lawful, EPA is issuing these tolerances without notice and opportunity for public comment as provided in section 408(l)(6) of FFDCA. Although these time-limited tolerances expire and are revoked on December 31, 2011, under section 408(l)(5) of

   FFDCA, residues of the pesticide not in excess of the amounts specified in the tolerances remaining in or on Bermudagrass, forage and

   Bermudagrass, hay after that date will not be unlawful, provided the pesticide was applied in a manner that was lawful under FIFRA, and the residues do not exceed a level that was authorized by these time- limited tolerances at the time of that application. EPA will take action to revoke these time-limited tolerances earlier if any experience with, scientific data on, or other relevant information on this pesticide indicate that the residues are not safe.

   Because these time-limited tolerances are being approved under emergency conditions, EPA has not made any decisions about whether nicosulfuron meets FIFRA's registration requirements for use on

   Bermudagrass, forage and Bermudagrass, hay or whether permanent tolerances for this use would be appropriate. Under these circumstances, EPA does not believe that these time-limited tolerance decisions serve as a basis for registration of nicosulfuron by a State for special local needs under FIFRA section 24(c). Nor do these tolerances serve as the basis for persons in any States other than

   Texas and Oklahoma to use this pesticide on the applicable crops under

   FIFRA section 18 absent the issuance of an emergency exemption applicable within that State. For additional information regarding the emergency exemptions for nicosulfuron, contact the Agency's

   Registration Division at the address provided under FOR FURTHER

   INFORMATION CONTACT.

4. Aggregate Risk Assessment and Determination of Safety

   Section 408(b)(2)(A)(i) of FFDCA allows EPA to establish a tolerance (the legal limit for a pesticide chemical residue in or on a food) only if EPA determines that the tolerance is ``safe.'' Section 408(b)(2)(A)(ii) of FFDCA defines ``safe'' to mean that ``there is a reasonable certainty that no harm will result from aggregate exposure to the pesticide chemical residue, including all anticipated dietary exposures and all other exposures for which there is reliable information.'' This includes exposure through drinking water and in residential settings, but does not include occupational exposure.

   Section 408(b)(2)(C) of FFDCA requires EPA to give special consideration to exposure of infants and children to the pesticide chemical residue in establishing a tolerance and to ``ensure that there is a reasonable certainty that no harm will result to infants and children from aggregate exposure to the pesticide chemical residue. . .

   .''

   Consistent with the factors specified in section 408(b)(2)(D) of

   FFDCA, EPA has reviewed the available scientific data and other relevant information in support of this action. EPA has sufficient data to assess the hazards of and to make a determination on aggregate exposure expected as a result of these emergency exemption requests and the time-limited tolerances for residues of nicosulfuron [3- pyridinecarboxamide, 2-((((4,6-dimethoxypyrimidin-2-yl) aminocarbonyl) aminosulfonyl))-N,N-dimethyl] in or on Bermudagrass, forage and

   Bermudagrass, hay at 10 ppm and 25 ppm respectively. EPA's assessment of exposures and risks associated with establishing time-limited tolerances follows.

   1. Toxicological Endpoints

      For hazards that have a threshold below which there is no appreciable risk, a toxicological point of departure (POD) is identified as the basis for derivation of reference values for risk assessment. The POD may be defined as the highest dose at which no adverse effects are observed (the NOAEL) in the toxicology study identified as appropriate for use in risk assessment. However, if a

      NOAEL cannot be determined, the lowest dose at which adverse effects of concern are identified (the LOAEL) or a benchmark dose (BMD) approach is sometimes used for risk assessment. Uncertainty/safety factors (UFs) are used in conjunction with the POD to take into account uncertainties inherent in the extrapolation from laboratory animal data to humans and in the variations in sensitivity among members of the human population as well as other unknowns. Safety is assessed for acute and chronic dietary risks by comparing aggregate food and water exposure to the pesticide to the acute population adjusted dose (aPAD) and chronic population adjusted dose (cPAD). The aPAD and cPAD are calculated by dividing the POD by all applicable UFs. Aggregate short-, intermediate-

      , and chronic-term risks are evaluated by comparing food, water, and residential exposure to the POD to ensure that the margin of exposure

      (MOE) called for by the product of all applicable UFs is not exceeded.

      This latter value is referred to as the level of concern (LOC).

      For non-threshold risks, the Agency assumes that any amount of exposure will lead to some degree of risk. Thus, the Agency estimates risk in terms of the probability of an occurrence of the adverse effect greater than that expected in a lifetime. For more information on the general principles EPA uses in risk characterization and a complete description of the risk assessment process, see http://www.epa.gov/ pesticides/factsheets/riskassess.htm.

      A summary of the toxicological endpoints for nicosulfuron used for human risk assessment can be found at http://www.regulations.gov in the

      July 14, 2009 document ``Nicosulfuron: Human Health Risk Assessment for

      Proposed Section 18 Use on Bermudagrass,'' pages 10 and 11 of 30 in docket ID number EPA-HQ-OPP-2009-0569.

   2. Exposure Assessment 1. Dietary exposure from food and feed uses. In evaluating dietary exposure to nicosulfuron, EPA considered exposure under the time- limited tolerances established by this action as well as exposures pursuant to existing tolerances in (40 CFR 180.454). EPA assessed dietary exposures from nicosulfuron in food as follows: i. Acute exposure. No acute effects were identified in the toxicological studies for nicosulfuron; therefore, a quantitative assessment of acute dietary exposure was not conducted. ii. Chronic exposure. In conducting the chronic dietary exposure assessment EPA used tolerance level residues and 100 percent crop treated (PCT) assumptions for all registered and proposed commodities. iii. Cancer. EPA has classified nicosulfuron as ``not likely to be carcinogenic to humans'' based on the lack of tumorigenic effects in rodent (rat and mice) bioassays at the limit doses and lack of mutagenic effects in the in vitro and in vivo genotoxicity assays. iv. Anticipated residue and PCT information. EPA did not use anticipated residue and/or PCT information in the dietary assessment for nicosulfuron. Tolerance level residues and/or 100 PCT were assumed for all registered and proposed food commodities.

      Page 8259

      2. Dietary exposure from drinking water. The Agency used screening level water exposure models in the dietary exposure analysis and risk assessment for nicosulfuron in drinking water. These simulation models take into account data on the physical, chemical, and fate/transport characteristics of nicosulfuron. Further information regarding EPA drinking water models used in pesticide exposure assessment can be found at http://www.epa.gov/oppefed1/models/water/index.htm.

      Based on the First Index Reservoir Screening Tool (FIRST) for surface water and the Screening Concentration in Ground Water (SCI-

      GROW) model for ground water, the estimated drinking water concentrations (EDWCs) of nicosulfuron for chronic exposures for non- cancer assessments are estimated to be 0.7 parts per billion (ppb) for surface water and 0.06 ppb for ground water.

      Modeled estimates of drinking water concentrations were directly entered into the dietary exposure model.

      For chronic dietary risk assessment, the water concentration of value 0.7 ppb was used to assess the contribution to drinking water. 3. From non-dietary exposure. The term ``residential exposure'' is used in this document to refer to non-occupational, non-dietary exposure (e.g., for lawn and garden pest control, indoor pest control, termiticides, and flea and tick control on pets).

      Nicosulfuron is not registered for any specific use patterns that would result in residential exposure. Therefore, a residential risk assessment was not conducted. 4. Cumulative effects from substances with a common mechanism of toxicity. Section 408(b)(2)(D)(v) of FFDCA requires that, when considering whether to establish, modify, or revoke a tolerance, the

      Agency consider ``available information'' concerning the cumulative effects of a particular pesticide's residues and ``other substances that have a common mechanism of toxicity.''

      EPA has not found nicosulfuron to share a common mechanism of toxicity with any other substances, and nicosulfuron does not appear to produce a toxic metabolite produced by other substances. For the purposes of this tolerance action, therefore, EPA has assumed that nicosulfuron does not have a common mechanism of toxicity with other substances. For information regarding EPA's efforts to determine which chemicals have a common mechanism of toxicity and to evaluate the cumulative effects of such chemicals, see the policy statements released by EPA's Office of Pesticide Programs concerning common mechanism determinations and procedures for cumulating effects from substances found to have a common mechanism on EPA's website at http:// www.epa.gov/pesticides/cumulative.

   3. Safety Factor for Infants and Children 1. In general. Section 408(b)(2)(C) of FFDCA provides that EPA shall apply an additional tenfold (10X) margin of safety for infants and children in the case of threshold effects to account for prenatal and postnatal toxicity and the completeness of the database on toxicity and exposure unless EPA determines based on reliable data that a different margin of safety will be safe for infants and children. This additional margin of safety is commonly referred to as the Food Quality

      Protection Act (FQPA) SF. In applying this provision, EPA either retains the default value of 10X, or uses a different additional SF when reliable data available to EPA support the choice of a different factor. 2. Prenatal and postnatal sensitivity. There is no quantitative or qualitative evidence of increased susceptibility observed following in utero nicosulfuron exposure to rats or rabbits in the prenatal developmental studies or following prenatal/postnatal exposure in young rats in the 2-generation reproduction study. The toxicity database is considered adequate and includes acceptable developmental toxicity studies in the rat and rabbit and a rat reproductive study.

      There were no developmental or reproductive effects observed in rats, but in rabbits (clinical signs, decreased body weight gain during dosing, increased abortions), postimplantation loss and decreased fetal body weight were observed at the maternal toxicity LOAEL. However, these effects were only observed at maternally toxic doses. 3. Conclusion. EPA has determined that reliable data show that the safety of infants and children would be adequately protected if the

      FQPA SF were reduced to 1X. That decision is based on the following findings: i. The toxicity database for nicosulfuron is considered adequate for purposes of assessing human health risk from this emergency exemption use. Available data suggest that nicosulfuron is poorly absorbed and that toxicity is low. Further, data suggest increased pre and/or post natal susceptibility was not observed. ii. The toxicity database for nicosulfuron is generally complete except for more recently required neurotoxicity and immunotoxicity testing requirements. iii. There is no evidence of neurotoxicity or immunotoxicity in the available studies. iv. There are no residual uncertainties with regard to assessing pre-and/or postnatal toxicity. v. There are no residential use patterns for this chemical and the exposure assessments are conservative and will not underestimate risks.

   4. Aggregate Risks and Determination of Safety

      EPA determines whether acute and chronic pesticide exposures are safe by comparing aggregate exposure estimates to the aPAD and cPAD.

      The aPAD and cPAD represent the highest safe exposures, taking into account all appropriate SFs. EPA calculates the aPAD and cPAD by dividing the POD by all applicable UFs. For linear cancer risks, EPA calculates the probability of additional cancer cases given the estimated aggregate exposure. Short-, intermediate-, and chronic-term risks are evaluated by comparing the estimated aggregate food, water, and residential exposure to the POD to ensure that the MOE called for by the product of all applicable UFs is not exceeded. 1. Acute risk. An acute aggregate risk assessment takes into account exposure estimates from acute dietary consumption of food and drinking water. None of the toxicology studies available for nicosulfuron indentified an adverse effect resulting from a single-oral exposure; therefore, dietary exposure presents no acute risks of concern. 2. Chronic risk. Using the exposure assumptions described in this unit for chronic exposure, EPA has concluded that chronic exposure to nicosulfuron from food and water will utilize